Electric fuse or cut-out.



B. W ALPOLE. ELECTRIC FUSE OR OUT-OUT. APPLICATION FILLED APR 12, 1912.

1,086,693 Patented Feb.,10,1914.

M [Val bah? 8 amm I B as Q UNITED STATES PATENT orrioa.

Biennium in. WALPOLE, or rnovrnnncn, nnonn rsnann.

ELECTRIC. rust: oncur-our.

Toall iohom it Jlay concern:

Be it known that I, BENJAMIN M. WAL- roLn agcitizen of the United States, and

residentflofthe cityfbfPiovidence, in the county-"of Providence and State of Rhode .Island, have invented certainnew and usefu'lllmprovements Electric Fuses-or Cut- O'uts, of which the following is a specifics.

",tion,

electric fuse or cu t-out, and has for its ob ,ject to provide a 'cu t out that will visibly .llhis inventionrelates to improvements in grand unmistakably/indicate when the inner fuse wire has .blown, and to perform this f of construction, as will be indicating operation without transmitting the electric current through the casing, thereby eliminating the dangerof receiving a shock at the pointof indication.

A further object of my invention is to provide a fuse or heat conductor of such a length that the heat in'the casing has had time to subside before the fusee burns through "the; opening in the sheath, thus eliminating the danger of the fire blowing out through this opening.

With these and other objects in view, the invention consists of certain novel features scribed and particularly appended claims.

j'Ofthe accompanylng drawings: Figure 1 is a central longitudinal sectional view poi ted out in'the through the sheath showing the main'fuse wire'and' the auxiliary fuse wire, also showing the fusee connected to the latter wire. Fig. 2- is an enlargedend view illustrating thearrangement 'by which the auxil- Fiaryfuse wire is'held suspended within the sheath and out of, contact with the same.

. -,auxiliary1 fuse wire-by means of which the Fig. 3 is an enlarged view of the auxiliary fuse wire showing the means by, which the fusee is connected to said wire. Fig. e'tis an'enlarged view showing the coils in the heat is intensified at a given point therein.

3 Figm 5- is an enlarged view of the cuptail showing the end of. a casing with the shaped capsule which receives the coils of the auxiliaryiwirathe end of the fusee and theflombustible cement by which the latter is connected to said wire. Fig. 6- is a de- Specification of Letters itatent.

ore fully de' resistance material.

Patented Feb. 10,1914.

Application filed April 12, 1912. Serial at. 680,311.

end of the auxiliary fuse wire extending through an eyelet in said casing.

Referring to the drawings, the inclosing tubular sheath 1 is preferably made of nonconducting material and is closed at its ends by perforated brass caps 22 which may be connected to binding posts, not shown, by

means of the clips 3-3.

4t designates the fuse wire which is made of any suitable soft metal adapted to inelt at a given temperature, the same being connected at either end to said caps and clips.

The new feature of my invention is the provision of an auxiliary fuse wire 5 of high resistance which is in practice extremely small in diameterand of material which per mits it to melt only at a comparatively high temperature, much higher than that of the main fuse, this higher temperature which is required to melt the auxiliary fuse wire serves to more surely ignite the fusee with which it comes in contact. In other words, as is found in practice a current of low voltage maybe passed through the main fuse wire which would rupture or melt the same and still not provide sufficient heat or arc to ignite a fusee in contact with the same, therefore in order to insure the ignition of the ends of the fuse wire thereby binding the same firmly in position without permitting the fuse wire ends to come 1n contact with the fiber portion of the casing. This wire is provided with a plufiality of coils or iayers 9 or other'suitable means for concentrating or intensifying the heat at one particular polnt therein said 0011s or layers being preferably near one end of the sheath. 1 have also provided a small cup-shaped member or capsule 10 of any suitable material, through a hole in the button of which one end of this wire is passed to draw the coils 9 within. the cup. A fusee 11 which is electrically inert, has one end passed through from the inner side of the sheath outward through small hole 12 into which it may be cemented bringing a portion of the fuse into view where its condition may be plainly observed as to whether it is blown or not. if desired a label of paper 14, or other suitable material, may be cemented or otherwise fastened over the hole 12 and the end of the fusee, so that when the fusee burns, this label will become charred, or otherwise discolored, and thus indicate that the fuse has blown. The opposite end 13 of this fuse is passed into the open mouth of the capsule 10 where it is held by means of a combustible cement with which "the capsule is now filled, The whole casing has a filling 13 of any suitable material, being preferably in a finely divided state, such as slaked lime, or the like, which permits of the escape of the vapor or gas formed upon the volatilization of the fuse link by an excessive current.

ln o 'ieration the cut-out is connected to the binding posts on its base, not shown, and when an excessive amount of current at tempts to pass therethrough a high degree of heat is generated in the main fuse wire which melts the same and breaks the circuit. The current. then in attempting to pass through the auxiliary fuse wire raises the same to a very high temperature which fempcrature is concentrated or localized. and intensified at the point where the wire is coiled, the heat there being sufficient to ignite the combustible cciucnt which will in turn ignite the fusee. This fusee may be wound in a coil or extend through nearly the whole length of the sheath so that a comparatively long period of time clapses, for instance a minute or more passes after the fuse has blown, before the fusee has burned its entire length and through the indicating opening. By this it will be seen that the indicating opening remains closed until the fire and smoke has died out and the pressure of generated gas is removed by passing out through the vent holes in the caps.

Another feature of my invention is that I employ an auxiliar fuse wire and arrange the same within the casing so that no portion of it is exposed, and have connected an electrically inert fusee to said auxiliary wire to conduct a small chain of fire from this wire to char the indicating label without conducting the electric current thereto,.thereby effectually eliminating thetpossibility of receiving an electrical shock by handling the cut-out casing while the same is in circuit, in other words, by my lIHPI'OVBdCOIlStIUCtlOII no shock can be received at the aperture where the indicator extends through the outer casing or sheath.

Then again, it is found in practice that where an auxiliary fuse wire extends out into contact with the fiber casing that when the fuse blows and the auxiliary wire be comes highly heated it often chars or even at times sets fire to the fiber casing, thereby in a measure practically defeating the very purpose of an inolosed fuse. To obviate this difficulty I have provided an auxiliary fuse wire which is not in any way connected to the fiber casing, it leads from the end caps to the interior of the casing where the heat is intensified or localized at a point remote from the casing. which leads from this point to the outer casing being of a low heat carrying capacity in the form of a small fusee which in itself would be incapable of creating heat enough to damage, burn or set fire to the fiber tube. In this way it will be seen that I have eliminated one of the greatest dangers of the ordinary indicating fuse where an auxiliary fuse wire leads directly to or through the fiber casing.

By fusee I mean a piece of slow burning material adapted to conduct a small chain of fire from one point to another.

I claim:

1. An electric cut-out comprising a cas ing, a main and-an auxiliary fuse wire passing through said-casing, each adapted to melt at different relative temperatures, means for localizing the heat generated by the current passing through the auxiliary wire, a fusee connected to said localizing point in the auxiliary fuse wire and leading through said casing to visibly indicate when the fuse has blown whereby a predetermined period of time elapses between the fusing and the indicating.

'An electric cut-out comprising an inclosing sheath having terminals at either end, a filling in said sheath, a main and an auxiliary fuse wire extending through said sheath both electrically connected to said terminals, a plurality of coils in said auxiliary wire for intensifying the heat at a given point in said wire, an indicating fusee connected to the coils in said auxiliary fuse wire and leading out through the wall of said sheath whereby an excessive current passing through said auxiliary wire will ignil'e said fusee.

3. An electric cut-out comprising an inclosing sheath having terminals at either end, a filling in said sheath, a main and an auxiliary fuse wire extending through said sheath both electrically connected to said terminal, a plurality of coils in said auxiliary wireifor intenslfying the heat at a given point 111 said wire, a fusee having one The indicating fusee.

end leading out through the wall of said I In testimony whereof I affix my signature sheath, a receptacle for receivmg and retainin presence of two Witnesses.

111 said coil also the opposite end of said 1 fuzee, and cement in said receptacle for BENJAMIN WALPOLE' 5 binding said fuse end to said wire whereby Witnesses:

' an excesswe current passing through said HOWARD E. BARLOW,

auxiliary Wire will ignite sa-ld fusee. E. I. OG EN. 

